Not only does the credit bureau max out their password length, you have a small list of available non-alphanumeric characters you can use, and no spaces. Also you cannot used a plused email address, and it had an issue with my self hosted email alias, forcing me to use my gmail address.
Both Experian and transunion had no password length limitations, nor did they require my username be my email address.
Update: I have been unable to log into my account for the last 3 days now. Every time I try I get a page saying to call customer service. After a total of 2 hours on hold I finally found the issue, you cannot connect to Equifax using a VPN. In addition there is no option for 2FA (not even email or sms) and they will hang up on you if you push the issue of their security being lax. Their reasoning for lax security and no vpn usage is "well all of our other customers are okay with this".
When I have to sign up for something on my phone I will use my pre Bitwarden default password. Then once I have a sec to sit down iPad or laptop I will change it to something more secure.
I am currently fighting with my wife and children to start using a password manager.
The funny thing about that is that I am currently on my laptop getting keepassxc set up. This post has somehow motivated me to finally get a password manager.
If it converts one person that is a good thing.
On your phone, you can select autofill, then ask bitwarden to generate a password, save and use that to register